I don’t know about local send specifically, but KDE Connect will do that. And if you have an FTP client on your phone, then yes you can easily spin up an FTP server on your local network and transfer files that way

In that case, this seems pretty reasonable – disclaimer: I can’t personally attest to the effectiveness of this

https://github.com/Lissy93/personal-security-checklist

Inform them of their rights: https://www.ilrc.org/red-cards-tarjetas-rojas#item-4476